June.1 



1Q17 J 



Excursion to Altona Bayt 17 



•has been noticed in regard to these or other aquatic forms of 

 hfe living in brackish water. A fair number of molluscan 

 shells, forty-nine in all, were gathered from the shore, a list of 

 which, collected by the members, is appended. The inter- 

 esting mixture of marine, estuarine, and fluviatile forms on 

 this shore, due to the influence of the Kororoit Creek, is worthy 

 of special note from a geological point of view, for similar 

 mixtures are met with in past periods, and may be due to 

 conditions like that at x-Vltona Bay. Many foraminifera were 

 also seen in the sands of the tidal pools, and, for the convenience 

 of members interested, there is given here a list of twenty-four 

 species, and a variety previously recorded by the leader from 

 this locality. On returning, two of the more ardent geologists 

 made a detour to visit the Altona Bay colliery, with the result 

 that some material with smaller fossils was gathered for sub- 

 sequent cleaning and examination. The old railway cutting 

 near the racecourse was examined, the evidence of which, as 

 part of a wide-spread and slightly uplifted coastal plain, is 

 quite clear. In this connection it was noted that there is an 

 absence of detrital or wind-blown material, such as would be 

 found in storm-driven and a^olian deposits, the foraminifera 

 and small mollusca being coiroded in situ rather than polished 

 or abraded.* 



The following is a list of the mollusca collected on the 

 excursion : — 



Marine. — Bivalves. — Area [Anadara) trapezia, Deshayes (old 

 shells, apparently washed from underlying platform), Area 

 (Barbatia) Jaseiata, Reeves, Pteria papiliojiaeea, Lam., sp., 

 Ostrea angasi, Sow., Modiola albieosta. Lam., Chamostrca albida, 

 Lam., sp., Roehejortia donacijormis, Angas, sp., Cardium tenui- 

 eostatmn. Lam., Venus {CMone) sealarina. Lam., Venus (Chione) 

 strigosa, Lam., Tellina deltoidalis, Lam., Maeoma maria.', T. 

 Woods, sp., Solctellina biradiata. Woods, sp. Chitons. — 

 Acanthochites exilis, Torr and Ashby. (?) Isehnochiton sp. 

 Gastcropods. — Haliotis ncBvosa, Martyn (in fragments), Subcmar- 

 ginulina rugosa, Quoy and Gaimard, sp. (juv.), Astralium 

 aureum, Jonas, sp., Astralium fimbriatum. Lam., sp. (juv.), 

 Phasianella anstralis, Gmelin, sp., Monodonta (Austroeoehlea) 

 constrieta, Diloina odontis. Woods, sp., Euehelus scabriuscukis, 

 Angas (juv.), Risella mdanostoma, Gmelin, sp., Natiea eoniea. 

 Lam., Natiea plumbca. Lam., Diala pagodula, A. Adams, Diala 

 picta, A. Adams, Diala monik\ A. Adams, Diala lauta, A. 

 Adams, Diala translueida (?), Hedley (deformed), Rissoa petterdi. 

 Brazier. Vernietus novcB-hollandicE, Rousseau, Bittium eerithium, 



♦See G. B. Pritchard, " The Recent Shell-Beds of Williams town," Vict. 

 Nat., vol. xxvi., 1909, pp. 20-24. 



